Abstract

Monosomic analysis method allows an in-depth genetic analysis which locates genes that control economically important features of wheat, to determine the linkage groups and map the genes in contrast to conventional methods of genetics. The purpose of our study was to examine resistance of introgressive wheat lines to yellow rust using an effective gene of yellow rust (Yr) Avocet isogenic lines and Kazakhstanskaya 126 monosomic lines. The lines 344 and 345 had a dominant and monogenic nature of inheritance for resistance to yellow rust. Resistance gene of the line 344 was found to be allelic to Yr 5 gene, but for the line 345, it was found to be allelic to Yr 10 gene of Avocet tester. The major resistance gene of the line 344 is localized on chromosome 5A (c² = 22.89). The Chi-square value of F₂ monosomic hybrid (Mono 5A Kazakhstanskaya 126 x line 344) was much higher than the values (c²= 0.05) for F₂control hybrids (Kazakhstanskaya 126 x line 344). Modifier genes were found on chromosomes 1A and 3B at the line 344 and on the 3A and 2B at the line 345, which reinforce the effects of major resistance genes. The critical chromosome in determining resistance to yellow rust of the line 345 was chromosome 6B (c² = 13.73). Those tolerant to yellow rust introgressive lines could be widely used as donors of stability in practical selection of soft wheat.

Key words: Introgressive line, monosomic analysis, Triticum timopheevii, hybridization, localization, chromosome, yellow rust (Yr).